1. Field of the Invention
The invention relates to integrated circuits with resistive networks and more particularly to those having a reduced mismatch. The invention can be advantageously applied to, but is not limited to, the gain control, in particular in steps of three decibels, of variable-gain amplifiers.
2. Description of the Related Art
The gain of the amplifier is defined by a ratio of resistances formed by a resistive circuit in the feedback loop of the operational amplifier and a resistive circuit connected in the input of this operational amplifier.
The resistances used for these circuits can exhibit a significant mismatch which is detrimental to the precision of the gain. The mismatch results from differences in values that exist between the various resistances of the circuit, for example the dimensional tolerances resulting from their fabrication process on the integrated circuit.
Accordingly, there exists a need for overcoming the disadvantages of the prior art as discussed above.